Windsurf Review: The Agentic IDE That Rewrites the Rules - Then Gets Rewritten Itself

Windsurf is the most turbulent success story in the AI coding space. In the span of a single year, the IDE formerly known as Codeium went from scrappy autocomplete plugin to a full agentic coding environment with over a million developers, attracted a $3 billion acquisition bid from OpenAI, saw that deal implode, lost its CEO and co-founder to Google in a $2.4 billion talent raid, and landed under Cognition's ownership - all while shipping a product that truly changes how developers write code. After two months of daily use, I can tell you the product is real. Whether the company's ongoing drama affects its trajectory is the harder question.

What Windsurf Actually Is

Let me situate this clearly. Windsurf is a VS Code fork - like Cursor - that wraps the familiar editor in a layer of agentic AI. The core pitch is that Cascade, the built-in AI agent, doesn't just suggest code. It understands your entire repository, tracks your actions in real time, remembers context between sessions, and can execute multi-step tasks across multiple files without you hand-holding it through each one.

The product launched as the Windsurf Editor in November 2024, replacing what was previously just the Codeium autocomplete extension. In April 2025, the company rebranded entirely to Windsurf. By mid-2025, they had 800,000+ active users and $82 million in annual recurring revenue. Then things got complicated - more on that later.

What matters for this review is what it's like to actually use the thing every day.

Cascade - The Agent That Anchors Everything

Cascade is the headline feature, and it earns its billing. Unlike traditional AI assistants that respond to isolated prompts, Cascade operates as a persistent agent with two primary modes: a Chat mode for questions and exploration, and a Code mode that can read, write, and execute across your entire project.

The standout capability is what Windsurf calls "Flow awareness." Cascade tracks everything you do - files you edit, terminal commands you run, clipboard contents, conversation history - and uses this shared timeline to infer your intent. In practice, this means you can start a refactor manually, and Cascade will pick up on your pattern and offer to continue it across the rest of the codebase. Or you can describe a task in natural language, and Cascade will plan the steps, edit the relevant files, run terminal commands, and verify the results.

Cascade tracks your edits, terminal commands, and clipboard in real time to maintain shared context.

I tested Cascade on a 40,000-line Django application. I asked it to migrate an authentication system from session-based to JWT tokens. Cascade identified the relevant files across the auth module, middleware, views, and tests. It created a migration plan, executed the changes in sequence, and ran the test suite to verify. The whole operation took about four minutes. It wasn't perfect - it missed a custom middleware hook that needed updating - but it caught roughly 90% of the necessary changes on the first pass. Fixing the remainder took another five minutes. Doing this manually would have been the better part of an afternoon.

The planning system deserves specific credit. A specialized planning agent runs in the background, continuously refining a long-term plan while the primary model focuses on executing immediate actions. This two-agent architecture means Cascade handles multi-step tasks more coherently than competitors that use a single-model approach. It rarely loses the thread of what it was doing, even on tasks that span 10-15 sequential operations.

Memories - Persistent Context That Actually Works

Cascade's Memories system is the feature that most distinguishes Windsurf from every other AI IDE I've tested. Between conversations, Cascade autonomously generates and stores "memories" about your codebase - architectural patterns, naming conventions, configuration quirks, dependency relationships. When you start a new session, those memories persist.

The practical impact is significant. By my second week of use, Cascade consistently produced code that matched my project's conventions without being reminded. It knew I used snake_case for Python, that the project relied on a custom ORM wrapper rather than raw SQLAlchemy, and that error responses followed a specific JSON structure. This kind of accumulated context is what makes the difference between an AI that creates plausible code and one that generates code that actually fits.

The limitation is that memories can occasionally become stale or slightly inaccurate as your codebase evolves. There is no straightforward way to audit or prune them. You can define explicit rules in .windsurf/ configuration files, but the autonomous memory system doesn't always defer to those rules when they conflict.

SWE-1 and SWE-1.5 - The Proprietary Models

Windsurf doesn't just rely on third-party models. The team developed its own SWE-1 family - purpose-built for software engineering tasks. The current flagship, SWE-1.5, claims near-Claude 4.5-level performance at 13x the speed. In my testing, that speed claim checks out. SWE-1.5 responses arrive noticeably faster than equivalent queries to Claude Sonnet or GPT-5 models.

On coding benchmarks, SWE-1 holds up respectably. Windsurf's internal evaluations show it performing close to frontier foundation models on conversational software engineering tasks and end-to-end task completion, while beating mid-tier alternatives. The SWE-1 Lite variant is available on the free tier with unlimited usage, which is genuinely generous.

The Pro tier also includes access to external models - Claude, GPT, Gemini - through Windsurf's credit system, so you're not locked into the proprietary models. But Cascade is optimized for SWE-1, and the integration shows. The proprietary models handle Windsurf-specific features like Memories and Flow awareness more reliably than the third-party alternatives.

Windsurf's Flow awareness system tracks your development timeline to foresee next steps.

Where It Falls Short

Windsurf's weaknesses are real and persistent enough to affect daily use.

Autocomplete reliability is the most frustrating issue. The tab-completion suggestions can fail to trigger, arrive late, or suggest irrelevant code. When it works, it's competitive with Cursor's inline suggestions. When it doesn't - and it doesn't roughly 15-20% of the time in my experience - the interruption breaks your rhythm. For an AI-first IDE, real-time assistance is table stakes, and inconsistency here is hard to forgive.

Stability during long sessions is another pain point. Cascade can handle short to medium tasks beautifully, but extended agent sessions - especially those involving large file trees or repeated terminal operations - can cause the editor to slow, lag, or crash outright. I experienced hard crashes twice in two months, both during intensive multi-file refactoring sessions that ran for 20+ minutes. Heavy projects can push CPU usage to 70-90%.

The free tier is truly restrictive. Twenty-five credits per month burns out in about three days of moderate use. It's enough to assess the product, not enough to use it seriously. This positions Windsurf's free tier as a trial rather than a real offering, which is fine - but they should be transparent about that rather than marketing it with the paid plans.

Pricing - The $15 Advantage

The Pro plan at $15/month with 500 credits is Windsurf's strongest competitive argument against Cursor's $20/month. That 25% savings matters over a year, and the included access to SWE-1 models (which have no credit cost) sweetens the deal further.

Each credit equals one prompt to a premium model - roughly $0.04 per interaction. If you stick primarily to SWE-1 and SWE-1.5 for daily work and reserve premium credits for complex tasks requiring Claude or GPT, 500 credits per month is manageable. Power users who lean heavily on frontier models will burn through credits faster and may need the $10 add-on packs.

Teams pricing at $30/user/month includes admin dashboards and centralized billing. Enterprise starts at custom pricing with RBAC, SSO, and hybrid deployment. At 200+ seats, credit allocation jumps to 1,000 per user.

The credit system can feel opaque. You need to internalize which models cost what, and the automatic refill option - while convenient - can surprise you with charges if you don't set a budget cap. Cursor's approach of offering unlimited slow requests with fast request quotas is arguably more predictable for planning purposes.

The Cognition Question

Any honest review of Windsurf in 2026 has to address the corporate situation. In July 2025, OpenAI's $3 billion acquisition bid collapsed after Microsoft raised IP concerns. Google then poached CEO Varun Mohan, co-founder Douglas Chen, and key R&D leaders in a $2.4 billion licensing and talent deal. Cognition - the company behind the Devin AI coding agent - bought what remained: the product, brand, IP, and remaining employees.

This matters because continuity matters in developer tools. Your IDE is the most intimate piece of software in your workflow. When key leadership leaves and ownership changes, the natural question is: will the product keep improving at the same pace?

The early signs under Cognition are cautiously positive. Wave 13 shipped in December 2025 with parallel multi-agent sessions, Git worktree support, and side-by-side Cascade panes. January 2026 brought Agent Skills. February 2026 added Gemini 3.1 Pro and GPT-5.3-Codex support. The cadence has not slowed. Whether that holds over the next twelve months - especially as Cognition integrates Windsurf with Devin - is the open question.

How It Compares

Against Cursor, Windsurf wins on price, proprietary model access, and the Memories system. Cursor wins on stability, autocomplete reliability, and the polish of its Composer mode. If you value deep codebase understanding and are willing to tolerate occasional rough edges, Windsurf is the stronger choice. If you want the most reliable daily driver with fewer surprises, Cursor remains the safer bet.

Against Claude Code CLI, Windsurf offers a more accessible GUI experience while Claude Code provides superior local execution and privacy. They solve different problems for different developer profiles.

For a broader comparison, our best AI coding assistants roundup covers the full landscape.

Strengths

• Cascade's multi-file reasoning is the best agentic workflow in any IDE - planning, execution, and verification in one flow
• Memories system learns your codebase conventions and persists context between sessions
• SWE-1 models are fast, competitive, and included at no credit cost on Pro
• $15/month pricing undercuts Cursor by 25% while offering unique capabilities
• Flow awareness tracks your actions in real time, reducing context-switching overhead
• MCP tool integration connects Cascade to external services (GitHub, Slack, Figma, Supabase)

Weaknesses

• Autocomplete inconsistency breaks rhythm - triggers fail or lag too frequently for an AI-first IDE
• Stability issues during long agent sessions, with crashes during intensive multi-file operations
• Free tier is too restrictive - 25 credits per month is a trial, not a plan
• Credit system opacity - requires mental math about model costs that competitors handle more transparently
• Cognition acquisition creates legitimate uncertainty about long-term product direction
• Memory staleness - no clean way to audit or prune Cascade's built up memories

The Verdict - 8.2/10

Windsurf is the most ambitious AI IDE on the market, and ambition counts for something. Cascade's agentic workflow - the combination of multi-file reasoning, persistent memory, Flow awareness, and proprietary SWE-1 models - creates a development experience that no competitor currently matches in scope. When everything clicks, it feels less like using a tool and more like working with a capable junior developer who knows your codebase by heart.

The rough edges are real. Autocomplete reliability needs to reach the same standard Cursor sets. Long-session stability needs work. The free tier needs to either be more generous or more honestly marketed. And the Cognition ownership transition, while handled well so far, introduces uncertainty that every developer considering a switch should weigh.

At $15/month, the risk is low. For professional developers working on large, complex codebases - especially those who value deep repository understanding and persistent AI context over raw autocomplete speed - Windsurf delivers capabilities that justify the subscription several times over. If you've been curious about what "agentic coding" actually means in practice, Windsurf is the most complete answer available today. Just know that you're boarding a ship that's still being rebuilt mid-voyage.

Sources

• Windsurf Official - The Best AI for Coding
• Windsurf Cascade - Agentic AI Features
• Windsurf Pricing Plans
• Windsurf Editor Changelog
• Introducing SWE-1.5: Our Fast Agent Model - Windsurf Blog
• Cognition's Acquisition of Windsurf - Cognition Blog
• Building a Magical AI Code Editor Used by Over 1 Million Developers - Lenny's Newsletter
• OpenAI's $3B Windsurf Move - VentureBeat
• Windsurf vs Cursor - Builder.io
• Cognition Valued at $10.2 Billion After Windsurf Purchase - CNBC